Levulinic acid (LA) (C5H8O3) (MW=116.115) is a top building block obtained from biomass-derived sugars. Advances in conversion of cellulose-derived biomass to date have resulted in selective yields of levulinic acid (LA) of up to about 80% at a production cost of about 5 cents (U.S.) per pound. Consequently, significant R&D efforts have now been extended to develop chemicals and fuels that originate from LA. LA-derived chemicals find application in the chemical industry as solvents and plasticizers, in the food industry and in other applications. However, current methods for upgrading biomass-derived sugars including hexoses (6-carbon sugars) and pentoses (5-carbon sugars) are limited by a lack of robust catalysts, high operating costs, and low yields. For example, y-valerolactone (GVL) (C5H8O2) (MW=110.116) is one potential intermediate in the production of transportation fuels. GVL may be produced from LA, which in turn can be derived from biomass-derived hexoses. However, a major drawback of this process is the need for precious metal catalysts to effect hydrogenation that impart a high cost for conversion of each unit of LA to GVL. Further, yields of chemicals stemming from dehydration of GVL such as methyl ethyl ketone (MEK) and acetone are small. The insignificant yields of these platform chemicals renders this process economically unsuitable for production of either the commodity chemicals or subsequent conversion into transportation fuels. Furthermore, the formation of cyclic intermediates can lead to formation of coke deposits during reaction that can rapidly deactivate necessary catalysts. Current upgrading methods for sugars are limited by a lack of catalyst robustness, high operating costs, and low yield.
Accordingly, new and efficient catalytic processes are needed that convert LA to selected conversion products including commodity chemicals such as MEK and acetone at appreciable yields suitable for use in bio-refineries for conversion into liquid transportation fuels. The present invention addresses these needs.